I've got a q9400 and set at my preferences on the page that all 4 cores should be used after that i contacted the project through the client to update the preferences but still only 2 threads were running simultaneously.
And suggestions?

Are there settings that I need to look at to see why? Or, perhaps, help these applets use the available resources?

Looking at my settings:
Switch between app between every 60min
On multiprocessor systems, use at most 100% of the processors
Use at most 82% of CPU time

(plenty of ram and cpu is available)

Change the % of cpu time back to 100%. It does nto do what you think it does, it does not stress the cpu only to 82%. What it does do is confusing...but if you think of your cpu slices of time, and having those slices of time available for the cpu to use as it sees fit. Now in your case the cpu runs at 100% for 8.2 slices then rests for 1.8 slices, then runs full out for 8.2 more slices of time, then rests for 1.8 slices etc, etc, etc. What most people think the setting does is only use, 82% in your case, of the cpu at any one time, leaving the rest for other stuff, well that is not how it works. Changing the setting away from 100% has also caused problems with Boinc.

Boinc ALWAYS runs at the lowest priority of any task on your pc, so even checking the mail will cause Boinc to stop doing its thing and then when your pc has some free cpu time available, Boinc takes back over and crunches. No to be honest that slow down is not as instant as we would like it to be but it is pretty fast. Most people never notice it, but some do and the drag can be annoying. When two machines are setup side by side you can see the miniscule slowdown when Boinc stops and something else runs and then Boinc starts back up again, but it is VERY slight in most instances.

When two machines are setup side by side you can see the miniscule slowdown when Boinc stops and something else runs and then Boinc starts back up again, but it is VERY slight in most instances.

To demonstrate that this is happening look at properties and you will see a difference in elapsed and cpu time. Elapsed is real time while cpu time is the time the cpu spends processing the work unit. I have a six hour preference and occasionally I note that the work unit is going to be another of these long running ones as its passed the 6 hour mark. I then check the cpu time and find it is only around 05:45:xx as I have been doing work on the computer.

Ubuntu 14.04-64, Boinc 7.2.42-64, Running Rosetta at 100%, only other project on this pc is wuprop(nci), 25 wus ready for crunching.

Memory? Are you sure you've enough??

Definitely a memory issue. Rosetta uses much more memory than most other BOINC projects. 500 MB is a common sight with some tasks going up to 1,000 MB and beyond.

Computer #2182015 says it has 984.45 MB available. Assuming that you are allowing BOINC to use 50% of your memory while the computer is in use you are limited to 492.23 MB. That will be enough to run 1 task most of the time, but you may struggle if you get any of the very big tasks.

If you want to use both cores then you will either need to install more memory or link the computer to another project that needs less memory. You may be able to process one Rosetta task at the same time as a task from another project, except when you get a very big Rosetta task.

I see often enough tasks need up to 1,8gb of ram per workunit. So 8gb would be good for a quad and a nonstop computing. Bad that 8gb are very expensive on ddr2. I limit quads to 2tasks only when they have 3 or 4 gb ram.DSKAG Austria Research Team: http://www.research.dskag.at